Increasingly, perches for laying hens are being made from metals and plastics. There is nothing in the literature regarding how easily birds jump between perches of different materials, or how their ability to do so changes with faecal contamination of the perches. Forty-four medium hybrid brown hens negotiated perches of wood (5 cm × 5 cm, rounded edges), metal (half-round section, diameter 4 cm) or poly-vinyl-chloride (PVC: circular section, diameter 4 cm), which were either clean or dirty (poultry manure 0.5–1.0 cm deep). The time to jump to the destination perch (0.75 m from the start perch), number of squats (pre-jumping behaviour), slips, failures to jump (in 300 s) and crashes were recorded. Compared to wood and metal perches, birds took significantly longer to jump from PVC perches when they were clean, but there was no difference when the perches were dirty. Birds slipped significantly more on clean metal or PVC perches compared to clean wood perches. The birds took significantly longer to jump from metal or wooden perches when they were dirty compared to when they were clean. These data may suggest that PVC is not a suitable material for perches. Slipperiness is important. The birds apparently found the metal and PVC perch more slippery than the wooden perch, although the metal perch did not cause the birds to delay jumping. A slippery perch may deter the birds from attempting to jump. Manure on the perches reduced the slipperiness of the metal and PVC perches. Once perches become dirty, any welfare issues concerning the risk of injury from slippery perches cease to be as important as the potential slipperiness of the manure itself.

The aim of this study was to assess the extent to which three non-invasive measures of welfare in laying hens (egg-shell quality, corticosteroid levels as measured from the birds' faeces, and behavioural preferences) were correlated over a period of five days in two groups of birds. One group had access to an enriched test area (bark chips on the floor and a tray of sprouted wheat); the other group had access to a comparably sized barren area (bare wire mesh floor). The measure of preference used was the amount of time hens spent in the test area as measured each day. It was predicted that birds with access to the less preferred environment would show higher levels of faecal corticosteroids and egg-shell anomalies. However, although the birds showed a preference for the enriched environment from Day 1, the other two measures did not follow the same pattern. Faecal corticosteroid metabolites showed an initial increase in both groups, which declined significantly by Day 4, with the ‘enriched’ birds in fact showing a trend for higher levels than the ‘barren’ birds. Shell thickness also showed a change over the five days, but with a different time course: declining to a minimal level on Day 3 and then rising again by Day 5. No measure of shell quality was significantly different between the two environments, but there was a trend for changes in shell thickness to be more pronounced in eggs from enriched birds. The results indicate the caution that needs to be exercised in using shell quality or corticosteroid measurements in isolation from assessments of what the animals themselves prefer.

It is not enough to study animal welfare; our responsibility is to promote it. To this end, we need to step out of our laboratories and develop robust protocols for assessing welfare in groups of animals on farms or in the laboratory. While these protocols must incorporate principles derived from detailed scientific study they will, in practice, need to be based on clinical observations and records that an assessor can acquire at a single visit. Such assessments must also be comprehensive: approaches based only on behaviour, or motivational state, or physical appearance, or performance records, can never tell the full story. The ‘Five Freedoms’ provide a comprehensive template that incorporates the different elements that define welfare state. However they only describe welfare at the time of observation. Protocols, for example, for on-farm assessment need to include measurements and records that provide evidence of long-term consequences of the quality of husbandry practices (eg body condition, chronic injuries). This paper reviews approaches developed at Bristol for the on-farm evaluation of welfare in dairy cows and free-range hens. The criteria used to assess welfare from clinical evidence were developed through expert consultation using the ‘Delphi’ review process. Experts were also asked to make value judgements as to the seriousness of different elements of poor welfare by indicating the point at which intervention would be necessary to resolve specific problems. This study identified a serious limitation of Quality Assurance schemes that seek to encompass many different elements of welfare into a single index that ranks overall welfare as acceptable or unacceptable. Specific farms had specific welfare problems and these required specific solutions.

Groups of end-of-lay (spent) hens were subjected to three different treatments on a short flat-belt conveyor. Observations of bird behaviour indicated that the incidences of wing flapping, loss of balance and alarm calling significantly increased when birds were conveyed up and down slopes in comparison to being conveyed horizontally (P<0.01). Birds were significantly more hesitant when approaching the incline compared to the horizontal (P<0.001). However, differences in behavioural responses were not reflected in times spent in tonic immobility or open-field tests. There were no significant differences for the three treatments. It is possible that human contact, before and after conveying, was a more significant fear stimulus than the treatment itself.

Soiling of nests in modified cages for laying hens might be reduced by using a wire mesh floor for the nest. However, use of such a material might be contrary to the preferences of the hens and compromise their welfare. Twenty-four laying hens were housed singly in modified cages which incorporated two nests. One nest had the standard perforated plastic floor whilst the other had one of two types of metal mesh floor. To determine whether hens preferred any one of the floor types for oviposition, the positions of the nest floors were swapped three times during 110 days. The hens showed a dichotomy in their behaviour after the nestfloors were swapped: the majority (12 of those making a consistent choice) continued to lay in the same nest location (ie location conservative) whereas 6-9 hens changed the nest in which they laid (ie floor type conservative). Only one of the floor type conservative hens preferred to lay on metal mesh. These results show that although the majority of hens showed no apparent aversion to laying in nests with metal mesh floors, 57-68 per cent preferred plastic floors and changed location to lay on this substrate.

Four aspects of lighting which may influence the behaviour and physiology of housed poultry are light intensity, photoperiod, light source and wavelength. These factors are frequently manipulated in an attempt to improve productivity and to facilitate management practices. This review examines the effects of such manipulation upon the welfare of the birds. The majority of papers on lighting in poultry houses deal with their effects upon performance, rather than on factors associated with behaviour and health which may impinge upon welfare. Data about the preferences of birds for different lighting conditions are almost entirely lacking, but the practice of housing birds in relatively low light intensity is considered likely to lead to sensory deprivation in species where vision is important. Tentative recommendations are given pending the results of future research as to appropriate light intensity, photoperiod and light sources for domestic poultry.

Increased pressure on the poultry industry by animal-rights organisations and environmentally-conscious consumers has led to the rising popularity of cage-free housing system for hens. One of the main dangers of cage-free housing systems is the possibility for laying hens to damage their keels. Keel bone fracture incidence rate ranges up to 85%, and can lead to extensive pain in any bird, and potentially be the cause of the death for a hen in a cage-free environment. It was reported that kneel bone damage observed in flocks housed in non-cage systems was 30 to 95% while in furnished cages it was 15 to 55%. The purpose of this review is to compare the prevalence of the problem found in the three main housing systems (conventional, enriched cage, and cage-free), discuss if such damage could affect the behaviour and production of laying hens, and provide potential solutions for reducing the prevalence of keel bone damage. Keel fractures can negatively affect a hen in its day-to-day life by causing pain and restricting its movements. The prevalence of keel bone damage varies considerably among the studies due to differences in the system design, genetic line, age and method for determining the keel damage, which makes difficult to compare the systems. The genetic selection, adequate nutrition and modifications in the house design have shown to be useful tools in reducing keel bone damage in laying hens.

Recent researches have showed that probiotics promote bone health in humans and rodents. The objective of this study was to determine if probiotics have the similar effects in laying hens. Ninety-six 60-week-old White Leghorn hens were assigned to four-hen cages based on their BW. The cages were randomly assigned to 1 of 4 treatments: a layer diet mixed with a commercial probiotic product (containing Enterococcus faecium, Pediococcus acidilactici, Bifidobacterium animalis and Lactobacillus reuteri) at 0, 0.5, 1.0 or 2.0 g/kg feed (Control, 0.5×, 1.0× and 2.0×) for 7 weeks. Cecal Bifidobacterium spp. counts were higher in all probiotic groups (P<0.001) compared with the control group. The percentage of unmarketable eggs (cracked and shell-less eggs) was decreased in both 0.5× and 2.0× groups compared with the control group (P=0.02), mainly due to the reduction of shell-less eggs (P=0.05). The increases in tibial and femoral mineral density and femoral mineral content (P=0.04, 0.03 and 0.02, respectively), with a concomitant trend of increases in humerus mineral density and tibial mineral content (P=0.07 and 0.08, respectively), occurred in the 2.0× group. However, the bone remodeling indicators of circulating osteocalcin and c-terminal telopeptide of type I collagen were similar among all groups (P>0.05). In addition, the plasma concentrations of cytokines (interleukin-1β, interleukin-6, interleukin-10, interferon-γ and tumor necrosis factor-α) and corticosterone as well as the levels of heterophil to lymphocyte ratio were similar between the 2.0× group and the control group (P>0.05). In line with these findings, no differences of cecal tonsil mRNA expressions of interleukin-1β, interleukin-6 and lipopolysaccharide-induced tumor necrosis factor-α factor were detected between these two groups (P>0.05). These results suggest that immune cytokines and corticosterone may not involve in the probiotic-induced improvement of eggshell quality and bone mineralization in laying hens. In conclusion, the dietary probiotic supplementation altered cecal microbiota composition, resulting in reduced shell-less egg production and improved bone mineralization in laying hens; and the dietary dose of the probiotic up to 2.0× did not cause negative stress reactions in laying hens.

This paper focuses on identification, risk status, exterior and production characteristics of two autochthonous hen breeds, the Banat Naked Neck and the Sombor Crested in the Republic of Serbia. These are two autochthonous breeds which have preserved the original characteristics of domestic poultry. Today they are reared in rural households or by breeders in small flocks. They mainly reproduce naturally, under brooding hens, with moderate attention or care from the farmer. These breeds are highly endangered. It is estimated that the total number of birds of the Banat Naked Neck breed ranges from 5,000 to 6,000 while the number of birds of the Sombor Crested breed is below 1,000. The limited number of birds per breed and the absence of experts and professional control in breeding have caused high variability of breed characteristics. These breeds are of combined type, used for production of meat and eggs; they have lower production characteristics, but are highly resistant and low-maintenance in regard to rearing and nutrition. To ensure the protection of these breeds from extinction, significant efforts have been made in the last decade. The preservation program has been developed for each breed in order to maintain the optimal number of animals to ensure a sufficient gene pool (by the ‘in situ’ conservation method), which could be used for the improvement of some traits in the selection of modern strains of poultry.

The present study investigated the effects of xanthophyll supplementation on production performance, antioxidant capacity (measured by glutathione peroxidase, superoxide dismutase (SOD), catalase, total antioxidant capacity (T-AOC), and reduced glutathione:oxidised glutathione ratio (GSH:GSSG)) and lipid peroxidation (measured by malondialdehyde (MDA)) in breeding hens and chicks. In Expt 1, 432 hens were fed diets supplemented with 0 (control group), 20 or 40 mg xanthophyll/kg diet. Blood samples were taken at 7, 14, 21, 28 and 35 d of the trial. Liver and jejunal mucosa were sampled at 35 d. Both xanthophyll groups improved serum SOD at 21 and 28 d, serum T-AOC at 21 d and liver T-AOC, and serum GSH:GSSG at 21, 28 and 35 d and liver GSH:GSSG. Xanthophylls also decreased serum MDA at 21 d in hens. Expt 2 was a 2 × 2 factorial design. Male chicks hatched from 0 or 40 mg in ovo xanthophyll/kg diet of hens were fed a diet containing either 0 or 40 mg xanthophyll/kg diet. Liver samples were collected at 0, 7, 14 and 21 d after hatching. Blood samples were also collected at 21 d. In ovo-deposited xanthophylls increased antioxidant capacity and decreased MDA in the liver mainly within 1 week after hatching. Maternal effects gradually vanished during 1–2 weeks after hatching. Dietary xanthophylls increased antioxidant capacity and decreased MDA in the liver and serum mainly from 2 weeks onwards. Data suggested that xanthophyll supplementation enhanced antioxidant capacity and reduced lipid peroxidation in different tissues of hens and chicks.

The present study investigated the effects of xanthophylls (containing 40 % of lutein and 60 % of zeaxanthin) on proinflammatory cytokine (IL-1β, IL-6, interferon (IFN)-γ and lipopolysaccharide-induced TNF-α factor (LITAF)) and anti-inflammatory cytokine (IL-4 and IL-10) expression of breeding hens and chicks. In Expt 1, a total of 432 hens were fed diets supplemented with 0 (as the control group), 20 or 40 mg/kg xanthophylls (six replicates per treatment). The liver, duodenum, jejunum and ileum were sampled at 35 d of the trial. The results showed that both levels of xanthophyll addition decreased IL-1β mRNA in the liver and jejunum, IL-6 mRNA in the liver, IFN-γ mRNA in the jejunum and LITAF mRNA in the liver compared to the control group. Expt 2 was a 2 × 2 factorial design. Male chicks hatched from 0 or 40 mg/kg xanthophyll diet of hens were fed a diet containing either 0 or 40 mg/kg xanthophylls. The liver, duodenum, jejunum and ileum were collected at 0, 7, 14 and 21 d after hatching. The results showed that in ovo xanthophylls decreased proinflammatory cytokine expression (IL-1β, IL-6, IFN-γ and LITAF) in the liver, duodenum, jejunum and ileum and increased anti-inflammatory cytokine expression (IL-4 and IL-10) in the liver, jejunum and ileum mainly at 0–7 d after hatching. In ovo effects gradually vanished and dietary effects began to work during 1–2 weeks after hatching. Dietary xanthophylls modulated proinflammatory cytokines (IL-1β, IL-6 and IFN-γ) in the liver, duodenum, jejunum and ileum and anti-inflammatory cytokine (IL-10) in the liver and jejunum mainly from 2 weeks onwards. In conclusion, xanthophylls could regulate proinflammatory and anti-inflammatory cytokine expression in different tissues of hens and chicks.

This paper reviews and presents data suggesting that the use of thyroxine (T4) to induce moult in poultry may be a viable alternative to previous methods involving feed withdrawal or feed avoidance. Studies completed in wild and domestic avian species have indicated that T4 is associated with the natural moulting process. Four experiments, spanning the range from using a purified, injectable form of T4 to a cost effective commercially available product, iodinated casein (economical source of T4) that can be fed to hens via a standard poultry ration, are presented. Since hens have full access to the diet during the induced moult, it is hoped that the procedure will be acceptable both to the poultry industry and to organizations concerned about the welfare of birds during this period of their annual cycle.

Estimates of variance components for five egg traits on 26265 laying hens were obtained by restricted maximum likelihood (REML) using several models. In the DOMFS model, the effects included hatch group, additive genetic, full-sib, parental dominance and inbreeding depression. In the DOM model, the full-sib effect was eliminated. In the FS model, the parental dominance effect was eliminated. In the ADD model, both the full-sib and the dominance effects were eliminated. In the DOMFS model, the estimates of the full-sib variance were generally higher for egg production traits and lower for egg characteristics than those of the parental dominance variance. However, this model has partially failed in separating these two components. When the full-sib effect was removed from the model, almost all of its estimated variance moved to the estimated parental dominance variance. When the parental dominance effect was removed from the model, almost all of its estimated variance moved to the estimated full-sib variance. The estimates obtained with REML and the DOM model were compared with those obtained by method R and tilde-hat methodologies. The d2 (ratio of dominance variance to total variance) differed by up to 86% for method R and up to 225% for tilde-hat. The h2 differed by up to 26 and 28%, respectively. For data sets that are too large to be analysed with REML, method R is a feasible alternative. A model for estimation of dominance variance should also include the full-sib or a similar effect, provided the data set is large. Similarly, to analyse egg production traits, the model should include at least the full-sib effect.

Fertility, generally considered as a trait of the two parents, is perhaps best defined as the interaction between the male and female gametes in the production of a viable zygote. Although zygote development and hatchability are traits of the embryo influenced by maternal effects, in most previous studies they have been considered to be female reproductive traits. The aim of this work was to study the influence of sire on fertility and hatchability traits and to estimate the (co)variance components of direct and maternal genetic effects under a Bayesian setting via Gibbs sampling. We measured the fertility of 6396 eggs and the hatchability of 5393 embryos on an individual basis. In addition, egg weight from 42 to 63 weeks of age (EW63) was recorded on an individual egg basis. The sire accounted for a significant amount of the variation infertility and hatchability. For direct heritability, the marginal posterior mean, for fertility and hatchability were almost equal (0·24). The maternal heritabilities for fertility and hatchability were 0·20 and 0·18, respectively. The direct heritability value for the egg weight trait was high. The direct-direct genetic correlation between egg weight and hatchability was negative and significant. The genetic correlations between the direct effect of the egg weight trait and maternal effects for fertility and hatchability were low, with variable signs, and were not significant. On the other hand, significant negative genetic correlations between direct and maternal effects of fertility and hatchability were obtained (the posterior means were –0·56 for FE and –0·55 for HC).

The procedures normally used for the removal of hens from cages at the end of their laying cycle and their subsequent transport to the slaughterhouse are described. Because 30% of live birds arriving at the slaughterhouse have been found to have one or more broken bones, discussion is focused on the principal factors involved in the aetiology of such lesions. These include the reduction in bone strength due to mineral depletion during lay, restricted physical movement and exercise within cages and the methods used to remove birds from their cages, in addition to the other sources of potential trauma associated with transportation from the farm to the processing plant.

Although spent hens are economically important, they are considered a by-product of the egg industry and efforts are therefore needed if better quality meat and higher returns are to be achieved. This review has compiled information on various aspects of spent hen processing and utilization. Meat and fat yields depend on age and weight of the birds with heavy hens producing better yields and better quality products than light weight birds. Except for muscle tissue removed almost intact by filleting machines, hand deboned meat is superior to mechanically deboned meat. Toughness of spent hen meat is no obstacle to the production of a variety of comminuted products. Such by-products as skin, gizzard, heart, ova yolk and fat can be utilized in emulsion-based chicken and other meat products. The use of phosphates to produce better quality spent hen meat products has been demonstrated. Improved deboning techniques and modern methods of meat processing are capable of enhancing the quality and value of meat from spent hens leading to greater demand and better financial returns.